Exploration and Development of the Tawau Geothermal Project, Malaysia

Abstract

Surface geothermal activity has been reported at Tawau in Sabah in NW Borneo, since 1960 and various aspects have been studied and reported irregularly through to the present. In 2010, Tawau Green Energy secured an exploration concession and carried out a comprehensive surface exploration program comprised of detailed geology, MT geophysics and geochemistry surveys. The results of this program have confirmed the existence of an active geothermal system centred on the SE slopes of Mt Maria, a young andesitic to dacitic volcano of Miocene to Quaternary age resulting from subduction on the NW facing Sulu arc. The resource is structurally controlled by a series of NW trending transcurrent faults and transpressional tectonics from the late Pliocene to the present day. The chemistry of surface springs suggest a deep underlying neutral chloride fluid rising and outflowing the SE and the South with a deep temperature of up to 240oC. An initial resource assessment has been made on the assumption that the resource can be developed with binary cycle power plant and this yields approx. 120MW of development capacity. TGE is now preparing to drill two deep exploration wells into the central portions of the Mount Maria upflow. These will commence on April 2014 and the results of the drilling program plus well testing are expected to be available for inclusion in this paper by the time it has to be finalised.